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Seminarios

Grabaciones en vídeo de los seminarios de la EBD
Documentos
— 20 Resultados por página
Mostrando el intervalo 81 - 100 de 126 resultados.
Nombre Tamaño Descargas
23_02_2017, Sharon Strauss
"Coexistence in close relatives: competition, facilitation and beyond". Summary: Closely related species are expected to share similar ecological niches, yet also compete more strongly with one another. How does that affect their coexistence? Using phylogenetic history to understand ecology has typically been approached with descriptive data sets. Here, I describe some studies in which we explicitly incorporate phylogeny in our experimental design to address the conundrum posed by Darwin.
671,2MB 1183
23_03_2017, Hyeun-Ji Lee
Título: Eco-evolutionary dynamics and the evolution of phenotypic plasticity Resumen: My research interests lie in how the interaction between the environment and the genotype can shape phenotypic variation within a species. Variation in phenotypic expression can either result from differential gene expression in response to environmental variability (environmentally-sensitive genes) and/or genetic adaptation to the varying environment along a geographical gradient. I am aiming to answer how the interplay of ecological factors and underlying genetic mechanisms give rise to phenotypic expression, and am incorporating an array of study questions and systems in my dissertation. In my first chapter, I am investigating an intriguing case of continental dwarfism in amphibians, focusing on the natterjack toad Epidalea calamita in southern Spain. The dwarf populations in Doñana are about 30% smaller than conspecific populations only about 60 km North, while lacking an efficient geographical barrier. To fully understand the various factors that are driving the intraspecific size variation in this species, I am incorporating standard metabolic rate analysis, stable isotope analysis, skeletochronolgy, male advertisement call description, female behavioral assays, and population genetics using neutral markers. From my second to fourth chapter, I am using the spadefoot toad Pelobates cultripes to study the evolution of phenotypic plasticity. For my second chapter I am raising and conducting water drop experiments on 10 populations of P. cultripes tadpoles, half of which originate from long lasting ponds and half from ephemeral ponds. Those are predicted to have evolved a different capacity to respond to pond desiccation and accelerate development, thus the phenotypic as well as transcriptomic reaction norm will vary across populations. In continuation of this experiment, I am testing the carry-over effects of the environmental challenges experienced in the larval stage in the terrestrial stage in my third chapter. Further, for my fourth chapter, I am planning on exploring the transgenerational effects of the capacity to respond to environmental stress and aim to describe the paternal and maternal effects separately. To do so, I am going to raise my toads to sexual maturity and conduct the water drop experiment on the F1 generation. For my fifth chapter, I am using the waterflea Daphnia magna, a study system that is more readily manipulated in lab conditions due to its fast reproductive cycle. This will allow me to conduct large-scale experiments comprising several generations and populations. I am planning on conducting an experiment on 2 populations of Daphnia, of which only one will receive a predator cue. Subsequently, I will describe how the phenotypically plastic responses of Daphnia have altered the population dynamics and build a model to describe the weight of phenotypic plasticity on population demography.?
242,4MB 1179
23_03_2017, Maria Jesus Rodriguez
Título: Ecological interactions between amphibian larvae and aquatic macrophytes Resumen: Despite the wealth of knowledge of ecology of amphibian larvae, their functional role within aquatic systems is relatively poorly studied. In this thesis we study the interactions between amphibian larvae and other trophic levels present in temporary ponds, especially with aquatic macrophytes. We focus on the effects of tadpole herbivory on native aquatic macrophytes, studying the consequences for the reproductive phenology and effort of the plants, under different contexts of long lasting vs. dry down water levels. Moreover, we are also assessing the effects of an invasive plant, Azolla filoculoides on native macrophytes and zooplankton, and how these effects can cascade onto amphibian larvae. Finally, we are also studying different aspects of the dispersal of seeds of aquatic macrophytes by tadpoles, and the possibility of secondary long distance dispersal as a consequence of bird predation on amphibian larvae.
244,4MB 1110
23_05_2019, Daniel Streicker
"Ecological and evolutionary insights into the dynamics and prevention of bat viruses" Bats are among the most important and least understood sources of emerging viral threats, including Ebola, SARS, and Nipah. The impacts of bat viruses are currently mitigated reactively, by treating the human or domestic animal hosts after the viruses appear and cause disease. In this talk, I aim to demonstrate how deeper understanding of transmission dynamics in bat reservoirs can empower strategic shifts towards preventing cross-species emergence. First, I will focus on vampire bat-transmitted rabies, an economically important virus affecting humans and livestock across Latin America. Data from a long-term mark-recapture study in Peru will provide ecological explanations for the inability of widespread bat culls to control rabies, and recent field experiments with biomarkers will demonstrate new prospects to prevent human and livestock rabies by applying self-spreading vaccines to wild bats. Next, by linking host and viral genetics with landscape data, I will show that we can forecast viral invasions into currently rabies-free areas, enabling use of life-saving human and animal vaccines prior to outbreaks. Finally, I will discuss a machine learning approach to rapidly identify the unknown animal origins of emerging viruses using signatures of evolutionary associations with specific host groups embedded into viral genomes. These three vignettes illustrate how combining ecological and evolutionary insights can overturn conventional wisdom on disease control and provide new avenues for preventive management of wildlife diseases.
530,1MB 489
23_06_2016, Simone Fontana, Regularity in the traits of individuals outcompetes other biodiversity metrics in explaining ecosystem properties
Simone Fontana Department of Aquatic Ecology Eawag: Swiss Federal Institute of Water Science and Technology Títle: Regularity in the traits of individuals outcompetes other biodiversity metrics in explaining ecosystem properties Abstract: Biodiversity affects ecosystem properties through changes in the trait composition and variation of natural communities. Using phytoplankton data obtained across 28 lakes we found that trait evenness - the regularity in distribution of morpho-physiological traits of individual organisms - was the strongest predictor of community resource use and biomass yield. Our results suggest that elucidating the mechanisms linking individual-level trait variation to community dynamics could improve our ability to forecast changes in ecosystem properties across environmental gradients.
533,9MB 1200
23_10_2019, Riitta Savolainen, Kari Vepsäläinen
What do socially parasitic Myrmica species teach us about speciation? Riitta Savolainen, Kari Vepsäläinen Department of Biosciences; University of Helsinki; Helsinki - Finland All ants are social, except for specific socially parasitic ants, inquilines. We will focus on inquilinism, the ultimate form of social parasitism, where the inquiline species practically lack own workforce and depend on their host for all colony tasks throughout their life cycle. We will concentrate on selected inquilines of the genus Myrmica. In this genus, several inquiline–host pairs are phylogenetically closest relatives to each other, such pairs having originated independently. This strongly suggests sympatric speciation of the inquiline from its host. We will present ecological, chemical and genetic support for this hypothesis. Finally, we will discuss the debated status of the inquiline of Myrmica rubra—whether it is an intraspecific parasite, an evolutionary lineage speciating from its host, or a good, though young, species.
320,3MB 738
23_11_2017, Miquel Arnedo
Miquel Arnedo Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Fac. Biologia, Universitat de Barcelona. Hopping, splitting or shifting: How to diversify in isolation? Insights from the spider world Islands are the test-tube experiments of evolutionary biologist and have played a fundamental role in our current understanding of diversification. Processes such as adaptive radiation and convergent evolution are trademarks of island biotas. However, isolated ecosystems do also offer ample opportunities for non-ecologically driven speciation. Because of their airborne dispersal capabilities, spiders are among the first settlers of remote islands and their predatory habits and ability to endure starvation makes them important component of other isolated ecosystems, such as caves and mountain tops. In this presentation, I will review some of the research conducted in my lab on the diversification of spiders on island-like systems and will discuss its main drivers, and the underlying similarities and idiosyncrasies of the evolutionary process in remote and extreme habitats.
731,1MB 560
24_02_2015 Magdalena Zabek, Population dynamics of feral horses in Australia
Australia has the largest population of feral horses (Equus ferus caballus) in the world, with some one million feral horses occupying the diverse and often remote Australian environments. Despite numerous concerns raised by government agencies, private landholders, and the general public on feral horse presence in the Australian ecosystems, there is lack of collective solutions on the management of this overabundant species. In this talk I focus on two studies from my PhD research that relate to measurement of the main vital parameters of the population of feral horses, which occupies a unique coniferous environment in Australia. I will first discuss a method for measuring reproduction and survivorship of the population. I show that estimation of these parameters could be used for modelling the annual population growth rate, which in turn could be used for long-term population management. I will then screen a documentary, which depicts for the first time the social organisation of feral horses in Australia in an attempt to understand the biology of the species and their relationship with the environment. With this work I demonstrate the value of understanding the ecology of feral animals and encourage future managers and government organisations to cooperate in the formulation of the appropriate feral horse management programs in Australia and elsewhere.
299,4MB 190
25_02_2016, Candelaria Rodríguez, Opportunistic pollination by birds and lizards in the Canary Islands
The reproductive success depend on the animal’s effectiveness and the context in which the mutualism occurs. The present thesis is about the interplay between these two aspects in the mutualism of pollination. We try to meet the challenge with a particular group of pollinators, opportunistic nectar-feeding vertebrates, in a particular context, oceanic islands. Due to their intrinsic ecological conditions, oceanic islands favour the appearance of depauperate and disharmonic assemblages of opportunistic pollinators, whose effectiveness and level of context dependence may differ significantly from those of continental systems. In the concrete case of the Canary Islands, passerine birds and lacertid lizards are frequent floral visitors of native flora, but their pollination ecology has remained almost unknown. For this reason, the present thesis follows a dual objective: first to experimentally demonstrate the effectiveness of birds and lizards as pollinators and analyse the potential differences between both functional groups, to then understand how their benefits on plant fitness vary under the presence of antagonists.
377,5MB 1834
25_10_2019, Erica Crespi
Effects of rising salinity in freshwater environments on amphibian health: Case studies of wood frogs Salinity of freshwater systems is increasing due to habitat modification, road salt run-off, industrial/mining wastes, and sea level rise. Because amphibians are adapted for life in freshwater systems, even small increases in salinity can be physiologically stressful, causing disruption of homeostasis with direct and indirect negative health consequences. In this seminar, I will discuss my research examining the health effects of anthropogenic increases in salinity across life history stages on wood frogs, Lithobates sylvaticus, in two different contexts: road salt run-off and habitat disturbance.
779,7MB 537
25_11_2015 Agustin Paviolo Proyecto Yaguarete, Investigaciones para conservar el jaguar en el Bosque Atlántico de Argentina
Dr. Agustín Paviolo Investigador del CONICET-Instituto de Biología Subtropical Facultad de Ciencias Forestales, Univ. Nac. de Misiones "Proyecto Yaguareté: Investigaciones para conservar el jaguar en el Bosque Atlántico de Argentina" El jaguar ha pedido cerca del 95% de su distribución en Argentina y esta críticamente amenazado. Desde el año 2003 desarrollamos investigaciones sobre el estado poblacional de la especie y sus principales amenazas para generar información que sirva de base para el desarrollo de estrategias de conservación. Para obtener la información básica hemos utilizado distintas metodologías incluyendo relevamientos con cámaras trampas, muestreo de participativos, seguimiento de individuos mediante collares GPS y técnicas genéticas. Para el análisis de datos hemos usado distintos enfoques desarrollando diferentes modelos de hábitat, y hemos utilizado modelos de captura-recaptura para la estimación de densidad. Hemos desarrollado un análisis de viabilidad poblacional y utilizamos modelos de conectividad del paisaje para evaluar distintas alternativas para mantener el hábitat de la especie. Durante la charla recorreré los distintos pasos que hemos dado durante el proceso y las nuevas investigaciones en marcha. Para más información sobre nuestro trabajo pueden visitar www.proyectoyagurete.com.ar o www.facebook.com/proyaguarete
297,9MB 723
26_01_2016, Love Dalén, Using palaeogenomes to explore the evolutionary history of Pleistocene Megafauna
Genomic data from samples that originate from different time periods (heterochronous samples) provide a unique opportunity to directly examine temporal changes in genome-wide diversity. Moreover, genomic data from different points in time can also be used to infer genome-wide mutation rates, which in turn can be used to assess the timing of demographic changes and population divergence events. The aim of this presentation is to showcase how such analyses can be done, using data from woolly mammoth and wolf as examples.
371,7MB 807
26_01_2017, Irene Paredes
Ponente: Irene Paredes Losada (Departamento de Ecología de Humedales) Título: Presión antrópica y calidad del agua en Doñana Resumen: Doñana es uno de los humedales más emblemáticos y de mayor extensión en Europa, aunque al igual que muchos otros humedales en el mundo, se encuentra amenazado por la continua presión de las actividades humanas. Una de las principales amenazas en Doñana es la contaminación por nutrientes debido a la intensa actividad agrícola, industrial y a los núcleos urbanos del entorno que, junto con las condiciones climáticas de esta región, han provocado episodios de eutrofización y han contribuido al establecimiento de nueva especies invasoras en la marisma. En este contexto, el objetivo de esta tesis es precisamente ampliar el conocimiento sobre el origen y la contribución relativa de las principales fuentes de nutrientes, en especial del nitrógeno, que llegan a la marisma a través de los arroyos vertientes. En primer lugar, se usarán datos históricos de concentración de nutrientes en la marisma de Doñana para determinar las variaciones interanuales y los factores potenciales (antrópicos y climáticos) que puedan explicar dichas variaciones durante el periodo de estudio (1995-2010). En segundo lugar, se explorarán las variaciones intranuales y espaciales de datos de concentración de nutrientes recogidos en la marisma y arroyos vertientes entre 2013 y 2016. En tercer lugar, se emplearán los isótopos estables para determinar el origen del nitrógeno que llega a los arroyos y a la marisma usando como indicadores dos especies de macrófitas acuáticas (castañuela y espadaña) y los nitratos (NO3-) disueltos en el agua. De ellos se obtendrá la firma isotópica del nitrógeno (?15N) con la que se analizará la variación espacial y se intentará cuantificar la contribución relativa de las distintas fuentes antrópicas (fertilizantes, aguas residuales) en el aporte de nitrógeno a estos sistemas acuáticos. Finalmente, tanto los resultados de concentración de nutrientes como los de isótopos estables se cruzarán con datos climáticos y de usos del suelo del entorno de Doñana para la interpretación de los mismos.?
271,3MB 1146
26_01_2017, Vanessa Cespedes
Ponente: Vanessa Céspedes Castejón (Departamento de Ecología de Humedales) Título: El hemiptero invasor Trichocorixa verticalis y sus interacciones con los coríxidos nativos y los ácaros acuáticos Resumen: El coríxido invasor americano Trichocorixa verticalis verticalis se citó por primera vez en la Península Ibérica en el Algarve en 1997 y desde entonces se ha extendido dentro y fuera de Doñana, encontrándose en el delta del Guadalquivir, así como en otros lugares de interés de conservación de Andalucía, incluyendo humedales RAMSAR y Reservas Naturales. El éxito de una invasión depende en gran medida de cómo se enfrente a nuevas condiciones ambientales, tanto abióticas (requerimientos fisicoquímicos) como biológicas (interacciones con competidores nativos, con depredadores y parásitos (especialmente ácaros acuáticos)). La presente tesis investiga el papel de estos factores (abióticos -bióticos) involucrados en una invasión, haciendo hincapié en el papel de los ácaros acuáticos como limitante de la invasión.
312,7MB 1151
26_10_2015, Mark JF Brown, Emerging diseases in bumblebees
Mark JF Brown (Professor in Evolutionary Ecology & Conservation Royal Holloway, University of London) Título: Emerging diseases in bumblebees Resumen: Emerging infectious diseases are a major threat to biodiversity and human health. Such diseases and the parasites/pathogens that cause them - in particular the Varroa mite and viruses - are known to be one of the main drivers of honey bee declines. I will talk about evidence for emerging infectious diseases in wild bees, particularly bumble bees, and whether they may play a role in bumble bee declines.
193,7MB 105
26_11_2018, Daniel Moen
"The evolution of diversity in morphology and species richness in frogs and toads of the world". Species richness and morphological diversity often vary drastically among groups of closely related organisms. Why are some groups more diverse than others? What are the ecological factors that drive such differences? In this talk, I will discuss two recent studies in which I examine the importance of microhabitat use in determining both body form, and thus morphological diversity in some groups, as well as differences in diversification rate, which closely relates to species diversity. In the first part of the talk, I will discuss morphological convergence and the scales (both temporal and spatial) at which it is typically observed. I then will describe a study that examined the relative importance of similar microhabitat use versus shared evolutionary history in determining body form in anurans (frogs and toads). In the second part of the talk, I will explore the relative importance of microhabitat use and climatic factors on diversification rates in anurans. Finally, I will describe recent work in my lab to better characterize and understand diversity in microhabitat, morphology, and functional performance across clades of frogs, highlighting recent fieldwork in Madagascar.
840,4MB 471
27_04_2017, Bruno Suarez
Título: Assembly patterns of mammal communities in a fragmented agroecosystem Resumen: The recognition of the structure of ecological communities is the main objective of community ecology. Observed patterns are fundamental to know the relative importance of the different factors that determine the structure of these ecological communities. This is because once the pattern is recognized, the question is to investigate which are the underlying processes causing that pattern. Currently, species local coexistence is better understood considering not only environmental factors or interactions among species, but also the regional distribution of the species under study. The general aim of the Thesis is to describe the assembly patterns of mammal communities in a fragmented agroecosystem and infer possible underlying processes that may cause these patterns. To do this, we follow a regional-to-local perspective.
267,4MB 1148
27_04_2017, Fran Oficialdegui
Invasión del cangrejo rojo americano, Procambarus clarkii: origen, mecanismos responsables de su éxito invasor y consecuencias de la invasión. Resumen: Las invasiones biológicas son consideradas, hoy en día, una de las principales y más severas causas de pérdida de biodiversidad, y específicamente, en ecosistemas dulceacuícolas. Desde un punto de vista multidisciplinar, esta tesis se centra en el estudio de una de las especies invasoras más conocidas y extendidas a lo largo de todo el mundo: el cangrejo rojo americano (Procambarus clarkii). En grandes líneas, los objetivos son (1) conocer la historia de la invasión en Europa desde un punto de vista filogeográfico, la estructura y conectividad entre las distintas poblaciones; (2) estudiar la expresión de proteínas para saber cómo los individuos hacen frente a nuevas condiciones abióticas; (3) evaluar la compleja interacción entre dos especies invasora de cangrejo (Procambarus clarkii y Pacifastacus leniusculus); y finalmente, evaluar las consecuencias de la invasión sobre (4) especies de macroinvertebrados, (5) anfibios a causa de la quitridiomicosis y (6) otras especies de cangrejos nativos europeos a consecuencia de la afanomicosis o peste del cangrejo.
310,1MB 1194
27_07_2017, Gregorio Moreno Rueda
The cost of begging: Does it exist? And if so, is it necessary to guarantee honest parent-offspring communication? Several theoretical models on the evolution of begging predicts that begging must be costly to be an honest, and evolutionarily stable, signal of need. However, the empirical search for begging cost has been unsuccessful, with proposed costs of begging, such as energy, attraction of predators, or reduced growth, not being universal or sufficient to explain the evolution of begging. Nonetheless, recent research points to a cost of begging in the form of reduced immunocompetence. Laboratory experiments with an array of bird species repetitively support the contention of a negative correlation between begging effort and immunocompetence. Moreover, my co-workers and I have shown that the negative impact of begging on immune system is not compensated by the increased ingest of food in fiercely begging nestlings. Furthermore, in a long-term field experiment, we have modified begging behaviour of pied flycatcher (Ficedula hypoleuca) nestlings, finding that begging level is under natural selection, and that its trade-off with immune system is key for understanding the impact of begging on fitness. In overall, although the subjacent cause of the relationship between begging and immune system remains unclear, recent findings suggest that offspring begging exaggeratedly may incur in an immunological cost, which has shaped the evolution of begging. However, these empirical results, demonstrating that begging is associated with a “cost”, do not demonstrate that such a cost is necessary for begging to be honest and evolutionarily stable. Begging, as other behaviours, might be inevitably associated to physiological processes, conducing to unavoidable trade-offs. In fact, several mathematical models predict that cheap begging may be honest and evolutionarily stable. The model in which I am working, as other models, predicts that begging does not require be costly to be honest, but the cost increases information contained in the signal.
315,5MB 1170
27_09_2018, John E. Banks
DECONSTRUCTING THE SURROGATE SPECIES CONCEPT: A LIFE HISTORY APPROACH TO THE PROTECTION OF ECOSYSTEM SERVICES JOHN E. BANKS (/California State University, Monterey Bay/) The use of the surrogate species concept is widespread in conservation science and environmental risk assessment, especially in efforts aimed at protecting species that are endangered or provide ecosystem services. Surrogates are often chosen on the basis of convenience or similarities in physiology or life history to species of concern, but few formal protocols exist for the choice of surrogates. At the same time, our ability to predict how species of concern will fare when subjected to anthropogenic disturbances such as environmental contaminants or toxicants is often based on misleading comparisons of static toxicity tests (e.g., the LC50). Here I present an alternative approach that features simple mathematical models parameterized with life history data, applied to different assemblages of species. I describe several case studies using data from diverse taxa including endangered salmonids and a suite of parasitoid wasps important for biological control in agroecosystems to illustrate how we can incorporate life history traits into models in order to better understand and predict population outcomes. I demonstrate that we cannot always reliably use the response of designated surrogate species to predict the fate of similar species exposed to the same disturbances. These results have implications for how we assess risk and set conservation policy in both managed and natural/semi-natural ecosystems.
505,5MB 610
— 20 Resultados por página
Mostrando el intervalo 81 - 100 de 126 resultados.